"Worse than we thought" has been one of the most durable phrases lately among those pushing for urgent action to stem the buildup of greenhouse gases linked to global warming.

But on one critically important metric -- how hot the planet will get from a doubling of the pre-industrial concentration of greenhouse gases, a k a "climate sensitivity" -- some climate researchers with substantial publication records are shifting toward the lower end of the warming spectrum.

There's still plenty of global warming and centuries of coastal retreats in the pipeline, so this is hardly a "benign" situation, as some have cast it.

But while plenty of other climate scientists hold firm to the idea that the full range of possible outcomes, including a disruptively dangerous warming of more than 4.5 degrees C. (8 degrees F.), remain in play, it's getting harder to see why the high-end projections are given much weight.

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In fact, there is an accumulating body of reviewed, published research shaving away the high end of the range of possible warming estimates from doubled carbon dioxide levels.

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(. . . recent work is trending toward the published low sensitivity findings from a decade ago from climate scientists best known for their relationships with libertarian groups.)